Many types of substrates including paper, non-woven laminates, foils, films, sheeting wood and other materials have been coated using an extrusion coating method. The extrusion coating process generally includes an extruder slot (cast) die mounted in a position above the substrate to be coated.
In the processes where nip rolls are utilized to apply a coating material to a substrate, the nip rolls add pressure to the substrate and coating material at the interface. However, the nip pressure used in extrusion coating technology causes distortion of the coating material and the substrate at the nip interface.
Previous attempts to laminate a three-dimensional material onto thin film materials which are particularly sensitive to excessive thermal loads have not met with success. In particular, the application of a three-dimensional apertured or non-apertured material to another three-dimensional apertured or non-apertured material has been especially difficult to achieve. In such cases, there must be sufficient thermal energy to cause the first three-dimensional non-apertured film material and the second three-dimensional non-apertured film material to melt and fuse together. Often these materials do not have sufficient mass to resist distortion under the required thermal load necessary to achieve a good bond between the film materials.
It is therefore an object of the present invention to provide an improved method for laminating a three-dimensional apertured or non-apertured film material to a flat or three-dimensional apertured or non-apertured film material.
It is another object of the present invention to provide an improved composite laminated film comprising a three-dimensional apertured or non-apertured film material laminated to a flat or three-dimensional apertured or non-apertured film material.
It is still another object of the present invention to provide an article suitable for use as a disposable absorbent product such as diapers, catamenial pads, surgical dressings and the like.